The following are the major studies presently under investigation in the Clinical Research Center, a multi-disciplinary facility: 1. The net mineralocorticoid effect in normal pregnancy is being studied by determining Na/K ratio in the stool, using the "wrong capsule," and Na/K ratio in saliva. Studies of the colonic-anal skin potential difference, and of the complete pattern of plasma steroids with possible effects on sodium transport are being initiated. 2. A major area of interest is in the effect of behavior therapy in improving homosexual and transvestite patients. 3. An analysis is under way of the effects of response prevention on compulsive behavior. 4. The effect of behavioral modification in the male homosexual on plasma testosterone levels is under study. 5. A study is underway of the short term effects of sexual arousal on plasma testosterone. 6. The complicated metabolic response to trauma is being investigated by on-line determination of R.Q in patients, and by determining correlation with hormonal and plasma amino acid changes. 7. A controlled trial of the beneficial effect of an andiogenic steroid on erythroiesis and clinical condition in sickle cell anemia has been instituted. 8. Studies of the metabolic pattern in lipa-atrophic diabetes have been initiated.